code: def _auread_before(source, raw_format_param):
      if source.ext not in [".wav", ".raw"]:
          raise ValueError(
              "path should contains filename extension and"
              " only .raw .wav formats are now supported."
          )
  
      if source.ext == ".raw" and raw_format_param is None:
          raise ValueError(
              "raw_format_param which contains sample_width, frame_rate, and channels"
              " need to be provided when read raw format audio file."
          )
  
file_path: nnabla/python/src/nnabla/utils/audio_utils/common.py
imports: from __future__ import division, absolute_import
  import os
  import numpy
label_desc: Use image node_id 4 for calling a global function with example usage: _auread_before(source, raw_format_param) without return types